Custennin II of Cornwall

Custennin II "the Saint" of Cornwall (500-560), also known as Custennin Gorneu or Constantine, was the king of Cornwall from 530 to 560, succeeding Cadwy of Cornwall and preceding Bledric of Cornwall.

Biography
Custennin was the son of Cadwy of Cornwall, and was the first monarch of the House of Devnent. Custennin was a Christian Breton. Custennin was known for immoral acts such as the murder of two royal youths inside of a church, but he mended his ways, and became known as "Custennin the Saint" or "Gorneu". When he died in 560, he was succeeded by Bledric of Cornwall.